Second language speaking can be the most intriguing and challenging among the language macro skills. It is perceived by many learners, teachers, and employers as the showcase of second language acquisition, mastery on which is both laborious and laden with individual fluctuations. The present study is aimed at scientifically scrutinizing speaking skills from various angles to portray a comprehensive picture of the multi-faceted linguistic behavior. To this purpose, the exploration constitutes the description of speaking and its typical forms of use in both educational and social settings, factors that contribute to speaking and influence its quality, the cognitive dimensions and processes of oral language production, commonly-used measures to rate (L2) speaking quality, and the operational techniques of speaking assessment for achievement and proficiency purposes. The endeavor is meant to assist second language materials developers, instructors, test makers, and more significantly, learners in coping with the complex skill more technically and effectively